The conventional wooden pallet is made up of top and bottom platforms each of which is formed by a plurality of spaced-apart wooden slats. The top and bottom platforms are joined by elongate wooden stringers. The wooden slats which make up the top and bottom platforms of the pallet are typically nailed or stapled to the elongate stringers. Alternatively, the platforms can be made of solid wooden sheets which are joined to elongate stringers.
The above-described wooden pallet, which often is assembled by hand, first requires the arrangement of the wooden slats which make up the pallet platforms into the desired configuration and then the joining of the slats to the elongate stringers by nailing or stapling. Such an assembly process is time consuming and expensive in that it requires extensive manual labor.
A pallet can also be constructed of a solid sheet or individual spaced-apart slats which are joined by elongate metal splines. The splines join the top and bottom platforms together in a contiguous structure. Such a pallet construction is shown in the commonly-owned pending application Ser. No. 203,618, filed Nov. 3, 1980, now abandoned. The above pallet construction including elongate metal splines readily lends itself to automated construction wherein the assembly of the wooden members to the splines could be carried out by machines. In this way, the need for extensive manual labor necessary in nailing or stapling the boards to the elongate supports is eliminated. An automated system of producing pallets would require very little in the way of labor.
Various types of methods and machinery for connecting a metal spline or connector to a wooden member have been proposed in the past. The manner of operation of the prior known machinery is to hold the wooden members stationary with respect to the metal splines or connectors and then force the spline or connector through the wood to embed the edges thereof in the wood. Such a method is time consuming in that one must first arrange the wooden members into the desired configuration and then force the splines into place. If a number of wooden members are used, such as in a pallet, the wood must first be arranged in a desired spacing and then while the slats are held in place, the splines must be forced into place to embed the edges in the wood. Such a process does not allow for a continuous manufacturing process. Additionally, manual labor in laying out the wooden slats in the desired arrangement is required.
Examples of prior known devices for assembling wooden members to metal splines or connectors are shown in the Kay U.S. Pat. No. 3,751,794, issued Aug. 14, 1973, the Kay U.S. Pat. No. 3,574,253, issued, Apr. 13, 1971, the Kay U.S. Pat. No. 3,714,696, issued Feb. 6, 1973, and the Kay U.S. Pat. No. 3,929,534, issued Dec. 30, 1975. The devices disclosed in the above patents all operate on the principle described above, i.e., ramming the metal splines or connectors into stationary pieces of wood.
For example, the Kay U.S. Pat. No. 3,574,253, which is used to assemble building units from wooden slats and interconnecting plates, constructs the building unit by first forming slots in the interior surfaces of the wooden members and then ramming the plates into place to connect the parallel, spaced-apart wooden members. The Kay U.S. Pat. No. 3,751,794 assembles a panel unit by placing the two opposing panel members in opposing beds which are pivotably mounted to move towards each other. Disposed within the beds are means for retaining the connector plates in place and cylinders for driving the plates through slots in the inner surfaces of the panels so as to embed the edges of the plates in the panels. If such an arrangement is used to assemble pallets, it may first be necessary to cut slots in the surfaces of the wooden slats of the pallet and then lay the slats in place on the opposing beds. Finally, the plates would be forced along the precut slots so as to embed the edges of the plates in the wooden slats. A multi-step operation of this sort would require extensive handling and positioning of the slats and connectors.
The Kay U.S. Pat. No. 3,751,794 also contemplates an assembly of panels wherein the panels are first positioned on opposing beds, as described above. The beds are then moved towards each other to force the panels onto the edges of the splines by applying sufficient pressure to the beds and panels carried thereon. In order to ensure that the panels are connected to the plates, the plates must be provided with a sharp edge portion.
The Kay U.S. Pat. No. 3,714,696 discloses another machine for advancing connector plates or splines along the length of a stationary wooden member so as to join the wooden member to the plates.
While various methods and machines for joining metal splines or connector plates to wooden members have been proposed, none provide a simple and continuous method for production of wooden pallets. In this regard, the above-described machines require the placement of the wooden members in position on a bed or stationary holding clamp prior to movement of the splines relative to the wooden members. A much more efficient arrangement would be to maintain the splines or connectors stationary relative to the wooden slats or members and drive the slats onto the edges of the splines. In this way, a continuous process wherein the arrangement of the wooden slats and the embedding on the edges of the splines is carried out in a single, continuous step is provided. Such a method and machine for carrying out this assembly process would allow for continuous construction of wooden pallets and eliminate much time consuming and expensive manual labor.